Hydraulic control device, control method of thereof, and automatic transmission
A hydraulic control device includes an oil pump for generating a hydraulic pressure by being rotated by power of a driving force source, a driving force source stopping unit that stops rotation of the driving force source when a predetermined condition holds, and a cut-off unit that cuts off transmission of the power from the driving force source to the oil pump when the driving force source rotates in a reverse direction as the rotation of the driving force source is stopped by the driving force source stopping unit.
1. A hydraulic control device, comprising:
an oil pump configured to generate a hydraulic pressure by being rotated only by power of an engine of a vehicle;
a driving force source stopping unit that stops rotation of the engine when the vehicle is running and a predetermined condition holds; and
a cut-off unit that cuts off transmission of the power from the engine to the oil pump when the engine rotates in a reverse direction as the rotation of the engine is stopped by the driving force source stopping unit.
2. The hydraulic control device according to claim 1 , wherein the cut-off unit is a one-way clutch which drives the oil pump only in one direction.
3. The hydraulic control device according to claim 2 , wherein the one-way clutch is provided between a rotating shaft of the engine and a sprocket coupled to the rotating shaft of the engine and adapted to transmit the rotation to the oil pump via a chain.
4. The hydraulic control device according to claim 2 , wherein the one-way clutch is provided between a pump rotating shaft of the oil pump and a sprocket which is coupled to the pump rotating shaft and to which the rotation of the engine is transmitted via a chain.
5. The hydraulic control device according to claim 2 , wherein:
the oil pump is driven by a pump rotating shaft coupled to a rotating shaft of the engine and coaxially provided with the rotating shaft; and
the one-way clutch is provided between the rotating shaft of the engine and the pump rotating shaft.
6. An automatic transmission including the hydraulic control device according to claim 1 , wherein the oil pump generates the hydraulic pressure by being rotated only by power of the engine.
7. A control method for controlling a hydraulic control device which comprises an oil pump configured to generate a hydraulic pressure by being rotated only by power of an engine of a vehicle, and a driving force source stopping unit that stops rotation of the engine when the vehicle is running and a predetermined condition holds, comprising:
cutting off transmission of the power from the engine to the oil pump when the engine rotates in a reverse direction as the rotation of the engine is stopped by the driving force source stopping unit.
8. A hydraulic control device, comprising:
an oil pump configured to generate a hydraulic pressure by being rotated only by power of an engine of a vehicle;
driving force source stopping means for stopping rotation of the engine when the vehicle is running and a predetermined condition holds; and
cut-off means for cutting off transmission of the power from the engine to the oil pump when the engine rotates in a reverse direction as the rotation of the engine is stopped by the driving force source stopping means.
9. The hydraulic control device according to claim 8 , wherein the cut-off means is a one-way clutch which drives the oil pump only in one direction.
10. The hydraulic control device according to claim 9 , wherein the one-way clutch is provided between a rotating shaft of the engine and a sprocket coupled to the rotating shaft of the engine and adapted to transmit the rotation to the oil pump via a chain.
11. The hydraulic control device according to claim 9 , wherein the one-way clutch is provided between a pump rotating shaft of the oil pump and a sprocket which is coupled to the pump rotating shaft and to which the rotation of the engine is transmitted via a chain.
12. The hydraulic control device according to claim 9 , wherein:
the oil pump is driven by a pump rotating shaft coupled to a rotating shaft of the engine and coaxially provided with the rotating shaft; and
the one-way clutch is provided between the rotating shaft of the engine and the pump rotating shaft.
13. An automatic transmission including the hydraulic control device according to claim 8 , wherein the oil pump generates the hydraulic pressure by being rotated only by power of the engine.